Electric heating device for laundry machines



July 27, 1926. 1,594,158

H. DE W. ELSE ELECTRIC HEATTN? DEVICE) FOR LAUNDRY MACHINES Filed July 31, 1924 ATTORNEY function.

Patented July 27, 1926,

HARRY DE WIT! ELSE, OF WII'JKINSBURG,

HOUSE ELECTRIC & MANUFACTURING VANIA.

PATENT OFFICE.

, PENNSYLVANIA, ASSIGNOR TO WESTING- OOMPANY, A CORPORATION OF PENNSYL- IEIIEC T BIC HEATING DEVICE FOR LAUNDRY MACHINES.

Application filed July 31,

T his invention relates to improvements in electric-heating elements for ironing machines and, more particularly, to thermostatically-controlled heating elements.

The object of the invention, generally stated, is the provision of an electric heating element that is simple and efficient in oper ation, readily and economically manufactured.- v

A more specific object of the invention is to provide for the automatic control of the supply of electrical energy to maintain the temperature between certain limits.

A further object of the invention is to efiecta cutting off of the supply of electrical energy in a manner that avoids damage to the apparatus through arcing.

It is also an object of the invention to provide for the variation of the limits of temperature at which the apparatus will Other objects of the invention will, in part, Joe obvious and in part appear hereinafter,

This invention, accordingly, isalisclosed inthe embodiment thereof shown in the accompanying drawing and comprises the features of construction, combination of ele-.

- ments and arrangement of parts which will be exemplified in the construction hereinafter set forth and the scope of the application of which will be indicated in the claims.

For a fuller understanding of the objects of the invention, reference should be had to the following detailed description, taken in connection with the accompanying drawing, in which Figure 1 is a perspective view of-an ironin'g machine, parts being broken away to show aheating element in accordance with this invention; p

Fig. 2 is a diagram of the connections showing the circuit controlled by the thermostat closed; and

Fig. 3 is a diagram of the connections showing the circuit controlled by the thermostat open. 7

Referring now to the drawing, 10 designates, generally, an ironing machine of a well-known type, provided with a roll 11 and a movable ironing shoe 12. Since the ironing shoe maybe moved toward and 1924. Serial No. 729,230.

away from the roll, it is the usual practice to provide the heat necessary for the 1ronticular design of ironing member, but may be constructed toconformto the shape and size of the ironing member. The heating element 1 1 may be mounted in any ironing member in any suitable manner, such, for example, as by fixing it in spaced relation to the ironing member by means of insulators and insulated screws. I

The heating element shown, generally, at 14, includes a plurality of separate resistance members 15, 16 and 17. As shown in Figs. 2 and 3, the resistance members 15 to 17, inclusive, are connected in parallel across the source of supply of electric energy, which, in this case, is the line wires 18. However, it will be readily understood that they may be connected in other ways and still give the desired heating efiect.

Referring now to Figs. 2 and 3, it will be seen that the resistance member 15 is connected across the-source of supply 18 and the supply of electric energy to the resistance member is controlled by means of a manually-operated'switch 13 interposed between it and the line. .The resistance mem bars 16 and 17 are connected in parallel and across the same source of supply of electric ioo damage from arcing, the winding of the magnet 21 is constructed from low-resistance wire so that sufficient current for its energization may flow therethrough upon applying a small voltage which may be supplied by connecting it across a relatively small portion of the resistance member 15.

Since it is desired to obtain automatic operation of the switch 19 to control the heating of the shoe 12, a thermostat, operable upon changes in temperature of the heating shoe, is provided for making and breaking the circuit of the electromagnet 21. The thermostat includes the ironing shoe 12 which, in this embodiment, carries suspended from its lower portion, a rod 28 of invar or some other suitable material not subject to changes in length by variations of temperature within the range required for carrying out ironing operations. As will be observed, in this particular construction, the rod 28 is suspended by means of two hangers 27 attached to the lower portion of the shoe.

In order to provide for the adjustment of the rod, it is slidably disposed in one of the hangers while a threaded portion of the rod engages an internal thread provided in an opening formed in the other hanger. which is located near the end of the shoe, as shown in Fig. 1. A hand wheel 30 is fixed to the rod 28 so that the latter may be adjusted in the hangers. Attached to the rod 28 is a contact member 24 preferably made from some metal not subject to corrosion and the formation of the coating of insulating material by the action of steam and the atmosphere.

Disposed .in alinement with the contact member 24 is a contact plate 23, the latter being fixed to a bar 26. Both members 23 and 26 are of some metal eflicient as a conductor of electricity and lines of magnetic force. The bar 26, as shown in Figs. 2 and 3, is carried by a spring 29, attached to the frame of the ironing machine and it forms the core of an electromagnet, the function of which will appear in a subsequent paragraph. I

Since it is desirable to establish a comparatively wide gap between the contact members 23 and 24 when the circuit is once broken, the core 26, carried by the spring 29 has mounted thereon a winding 22, connectcd in series with the winding of the eloctromagnet 21. The electromagnci consisting of the Winding 22 and the core 26, cooperates with the armature 25 carried by the rod 28 to establish a magnetic circuit to retain the contact members 23 and 24 in engagement as the rod 28 moves to the right until the spring has been energized sufliciently to overcome the magnetic attraction, when the spring will function to carry the contact plate 23 away from the contact member 24. On examining Figs. 2 and 3, it will be seen that the circuit of the electromagnet 21 includes the winding 22, core 26, plate 23, contact member 24 and a portion of the resistance member 15, all connected in series.

It will be readily understood that, as the rod 28 is projected against the plate 23, the spring 29 will be flexed. Thus, the spring 29 has a second function, in that it serves to protect the parts of the apparatus from damage during operation if the rod 28 has not been set with great accuracy.

In mounting the switches 13 and 19, a switch box 32 may be provided and attached to the ironing machine frame, as shown in Fig. 1. In this particular construction, the switch 19 is located in the switch box- 32 while the switch 13 is disposed on its front wall so that it may be manually operated without opening the box. The conductors leading from the source of supply 18 to the switches and the heating elements, may be enclosed in conduits, such as 33.

In operation, when it is desired to heat the ironing shoe 12, the rod 28 is set to place the contact members 23 and 24 in engagement and then the switch 13 is manually operated, connecting the resistance member 15 of the heating element across the source of electric energy 18. Since the circuit of the electromagnet 21 is closed, the winding of the electromagnet is connected across a. portion of the resistance member 15. This results in the energization of the electromagnet 21 and the closing of the switch 19, connecting the resistance members Y16 and 17 of the heating element in parallel across the source of electric energy. The heating element 14 is now operating at full capacity and the shoe is quickly brought to the desired temperature.

As the temperature of the shoe gradually increases, it expands, drawing the rod 28. as shown in Figs. 2 and 3, to the right. During the first part of the movement of the rod 28 to the right, the energized solenoid 22, which has established a magnetic circuit through the armature 25, causes the spring 29 to follow, maintaining the contact members 23 and 24 in engagement. However, when the rod 28 has moved a predetermined distance, the spring 29 is sufficiently energized to hold the plate 23 against further movement and the members 23 and 24 are separated. Instantaneously with the breaking of the contact between members 23 and 24, the solenoid 22 is de-energized and the spring 29 acts to effect a movement of the contact plate 23 away from contact member 24. The spring 23 may vibrate, but the amplitude of vibration will continuually decrease so that the contact members 23 and 24 are not brought into engagement.

In this particular construction, an electromagnet is shown for maintaining the concontracts upon stood that any permanent magnet might be substituted therefor. In fact, efiicient operation may be effected without the use of a magnet.

In designing the resistance member 15, its heating capacity is limited so that it will not raise the temperature of the ironing shoe above the ironing temperature when the machine is not in operation. Ifnow articles to be ironed are introduced into the ironing machine, the shoe 12 gives off its heat to the articles being ironed, it contracts and pro jects the rod 28, as viewed in Figs. 2 and 3, to the left, establishing contact between the contact members 23 and 24, again comgleting the circuitof the electromagnet 21.

his results in the closing of the switch 19 and the con'necting of the -resistance members-16 and 17 of theheating element across the source of electric energy. The heating element 14 is again at full capacity and the shoe is maintained at an ironing temperature.

While the illustrated example constitutes a practical embodiment of my invention, do not limit myself strictly to the exact details herein illustrated, since, manifestly, the same can be considerably varied without departing from the spirit of the invention, as defined in the appended claims.

I claim as my invention:

1. In an ironing machine, in combina-.

tion, an ironing member which expands and changes in temperature, a variable electrical heating element for the ironing member, and means disposed for actuation as the ironing member expands and contracts to control the heating element.

2. In an ironing machine, in combination, an ironing member subject to changes in size upon changes in temperature, heating element for the ironing member, means for controlling the heat delivered by the heating element, said control means being disposed for operation by the ironing member as it changes in size.

3. An automatic heat control for ironing machines comprising, in combination, an

ironing member sub ect to changes in size upon changes in temperature, an electrical. heating element for the ironing member, means for varyin the heating capacity of the element, and means for actuating said heat-varying means disposed to be operated by the ironing member as it changes in size.

4. In an ironing machine. in combination, an ironing member, a plurality of resistance members adapted to be cut into and out of an electric circuit disposed to heat said ironing mei'nber,'switching means operable to vary the number of resistance members in said circuit, and a thermostat operable Iv source of electr1c energy an electrical.

QPY

on changesfin temperature of said ironing member to efiect the operation of sai switching means, said ironing member being the controlling member of the thermostat.

5. In an ironing machine, in combination, an ironing member, a plurality of resistance members adapted to be cut into and out of an electric circuit disposed to heat the ironing member, a switch adapted to vary the number of resistance members in the circuit and means operable upon the ex )ansion and contraction of the ironing mem r to effect the operation of said switch.

6. In an ironing machine, in combination, an ironing member, a plurality of resistance members adapted to be cut into and out of an electric circuit dis osed to heat the ironing member, connected in parallel, a switch ada ted to vary the number of resistance mem ers in the circuit, and meansoperable upon the expansion and contraction of the ironing memberto effect the operation of the switch.

7 In an ironingmachine, in combination, an ironing member, a pluralityof resistance members adapted to be connected across a disposed to heat said ironing member, an electrically-operated switch adapted to vary the number 0 resistance members connected across said source of electric energy, and a thermostat. adapted to control the operation of said switch, said ironing member being one of the members of the thermostat, thereby to control theoperati'on of said switch by the expansion and contraction of the ironing member.

8. In an ironing machine, in combination, an ironing member, a plurality of resistance members adapted to be connected across a source of electric energy disposed to heat said ironing member, an electrically-operated switch adapted to vary the number 0 resistance members connected across sai source of electric energy, and a thermostat operable to make and break said switch circuit to control the operation of said switch, said ironing member being one of the members of'the thermostat, thereby to control the operation of the switch by the expansion and contraction of the ironing member.

9. "In an ironing machine, in combination, an ironing member, a plurality of resistance members adapted to be connected across a Ill ber, the other member of the thermostat bemg disposed for movement toward and away from the ironing member.

10. In an ironing machine, in combination, an ironing member, a plurality of resistance members adapted to be connected across a source of electric energy disposed to heat said ironing member, an electricallyoperated switch adapted to vary the number of resistance members connected across said source of electrical energy, and a thermostat cooperative to control the operation of said switch, said thermostat comprising a contact member carried by the ironing member and connected in the switch circuit, and a second contact member adapted to move away from said first contact member on the breaking of the switch circuit.

11. In an ironing. machine, in combination, co-operative ironing members, a plurality of electric resistance members adapted to be connected to a source of supply of electric energy disposed to heat an ironing member, a manually operated switch adapted to t connect a resistance member across said source of supply, an electrically operated switch adapted to connect the other resistance members across a source of supply, said electrically-operated switch being connected across a portion of the resistance member controlled by the manually operated switch and means automatically operable to make and break said switch circuit.

12'. In an ironing machine, in combination, an ironing member, a heating element disposed to heat the ironing member, an electrically operated switch adapted to' vary the capacity of the heating element, an electric circuit to control the operation of said switch, and a thermostat operable to make and break said circuit, said thermostat including the ironing member, a contact member carried by the ironing member and disposed to move upon the expansion and contraction of the latter, a second contact mem' ber disposed to receive said first-mentioned contact member, said second contact member being disposed for movement.

13. In an ironing machine, in combination, an ironing member, a. heating element disposed to heat the ironing member, an electrically operated switch adapted to vary the capacity of the heating element, an electricj circuit to control the operation of said switch, and a thermostat operable to make and break said circuit, said thermostat including the ironing member, a contact member carried by the ironing member and disposed to move upon the expansion and contraction of the latter, a second contact member disposed to receive said first-mentioned contact member, said second contact member being disposed for movement, a magnet carried by one of said contact members, and an armature by the other contact member, thereby to eifect a movement of the contact members together.

In testimony whereof, I have hereunto subscribed my name this eighth day of July 1924.

HARRY D. ELSE. 

